newton, watertown, cambridge, waltham, belmont, and all of boston, affected by this lockdown here as police search for a suspect in the marathon -- the boston marathon bomber case and also the same suspect suspected of murdering a police officer here overnight. his name is dzhokhar dzhokhar. he is just 19 years old. police telling us he is willing to die on this standoff and heavily -- and he is heavily armed. kelly: jim, is there any word as to how they zeroed in on these wo men so quickly? >> yesterday, over the last several days, they have been going over every inch of video, every photograph that they have from the marathon, from that area around the finish line where the bombs went off. by doing that, they were able to isolate two people with extremely suspiciousty. they were able to follow them with all the surveillance cameras through the finish line area. they saw one of the two men dropping off a package in a backpack in the precise location where one of the two bombs went off. those two men, they put out pictures of yesterday.mber, youe remember, you might have seen. they r